This application is related to Japanese Patent Application No. 2000-251309 filed on Aug. 22, 2000, the contents of which are hereby incorporated by reference.
1. Field of the Invention
The present invention relates to an expansion valve which adjusts a flow amount of refrigerant flowing into an evaporator so that a super-heating degree of refrigerant at an outlet of the evaporator is maintained at a predetermined value in a refrigerant cycle. More particularly, the present invention relates to a noise reduction due to a vibration-proof member of the expansion valve.
2. Description of Related Art
In JP-A-9-303905, an insulator is attached to a refrigerant outlet pipe of an expansion valve, so that a vibration in the refrigerant outlet pipe connected to the expansion valve is restricted. However, in this case, because the vibration caused in the expansion valve cannot be restricted, it is impossible to sufficiently reduce noise generated in the expansion valve.
In view of the foregoing problems, it is an object of the present invention to provide an expansion valve, in which a material cost of a vibration-proof member can be reduced and pipe operation performance can be improved, while a sufficient noise-reducing effect can be maintained.
According to the present invention, in an expansion valve for a refrigerant cycle including an evaporator for evaporating refrigerant, the expansion valve is disposed to adjust an amount of refrigerant flowing into the evaporator so that a super-heating degree of refrigerant at an outlet side of the evaporator becomes a predetermined value. In the expansion valve, a body case has therein a restriction passage for decompressing and expanding high-pressure side liquid refrigerant in the refrigerant cycle, a valve body is disposed in the body case for adjusting an opening degree of the restriction passage, a diaphragm case is disposed at one end side of the body case, a diaphragm is disposed in the diaphragm case to partition a first pressure chamber and a second pressure chamber in the diaphragm case and to displace the valve body in accordance with a pressure difference between both the first and second pressure chambers, and a single vibration-proof member made of a rubber material is disposed to cover only a part of the body case and the diaphragm case. Because the vibration-proof member is provided to cover the diaphragm case, vibration in the diaphragm case can be restricted by the weight of the vibration-proof member. In addition, the diaphragm case is connected to the body case by the vibration-proof member, a free vibration of the diaphragm case can be effectively restricted.
Because the vibration-proof member covers only a part of the vibration-proof member and the diaphragm case, a surface dimension of the vibration-proof member can be greatly reduced as compared with a case where the vibration-proof member covers all the expansion valve, while the vibration in the diaphragm case can be sufficiently reduced.
Preferably, the body case has a width dimension in a direction corresponding to the width of the vibration-proof member, and the width dimension of the body case is larger than the width of the vibration-proof member. Therefore, the vibration-proof member can be readily bonded onto the diaphragm case and the body case.
The expansion valve is a box type in which the body case is connected to a refrigerant pipe through which refrigerant flows, at one side in a width direction, and the vibration-proof member is disposed to be bonded onto the diaphragm case and a part of opposite side surfaces df the body case in a direction approximately perpendicular to the width direction and an extending direction of the body case. Accordingly, the refrigerant pipe can be readily connected to or detached from the body case, in the expansion valve. As a result, material cost of the vibration-proof member can be reduced and pipe operation performance can be improved, while a sufficient noise-reducing effect can be maintained in the expansion valve.